Does anyone know what determines the amount of arp tries a router will make? I have different behaviors with two devices, if I try to traceroute to a non-existent host on a subnet that belongs to an interface on the router, a Linux box will try to arp 3 times and then return a host un-reacheable icmp message. Junos will continuosly try to arp and not return anything. Is there a sysctl value that determines this or anything at all.
On linux, you're interested in:
The linux kernel will return an icmp host unreachable to the original sending process if it's unable to resolve an ARP after the
In BSD (including Junos), you can set it thusly:
This sets the number of retries, so set it to
If you were doing traceroutes to a non-existent local address on Linux, you should have seen 3 ARPs followed by traceroute exiting with
If you were doing traceroutes to a non-existent local address on Junos (BSD), you should see 5 ARPs followed by traceroute printing